Buggy code:
public class StringUtils { public static final String EMPTY = "" ; public static final int INDEX_NOT_FOUND = - 1 ; private static final int PAD_LIMIT = 8192 ; private static final Pattern WHITESPACE_BLOCK = Pattern . compile ( "\\s+" ) ; public StringUtils ( ) { } public static boolean isEmpty ( CharSequence cs ) { } public static boolean isNotEmpty ( CharSequence cs ) { } public static boolean isBlank ( CharSequence cs ) { } public static boolean isNotBlank ( CharSequence cs ) { } public static String trim ( String str ) { } public static String trimToNull ( String str ) { } public static String trimToEmpty ( String str ) { } public static String strip ( String str ) { } public static String stripToNull ( String str ) { } public static String stripToEmpty ( String str ) { } public static String strip ( String str , String stripChars ) { } public static String stripStart ( String str , String stripChars ) { } public static String stripEnd ( String str , String stripChars ) { } public static String [ ] stripAll ( String ... strs ) { } public static String [ ] stripAll ( String [ ] strs , String stripChars ) { } <START_BUG> public static String stripAccents ( CharSequence input ) { <END_BUG> if ( input == null ) { return null ; } try { String result = null ; if ( StringUtils . java6Available ) { result = StringUtils . removeAccentsJava6 ( input ) ; } else if ( StringUtils . sunAvailable ) { result = StringUtils . removeAccentsSUN ( input ) ; } else { throw new UnsupportedOperationException ( "The<seq2seq4repair_space>stripAccents(CharSequence)<seq2seq4repair_space>method<seq2seq4repair_space>requires<seq2seq4repair_space>at<seq2seq4repair_space>least<seq2seq4repair_space>Java<seq2seq4repair_space>1.6<seq2seq4repair_space>or<seq2seq4repair_space>a<seq2seq4repair_space>Sun<seq2seq4repair_space>JVM" ) ; } return result ; } catch ( IllegalArgumentException iae ) { throw new RuntimeException ( "IllegalArgumentException<seq2seq4repair_space>occurred" , iae ) ; } catch ( IllegalAccessException iae ) { throw new RuntimeException ( "IllegalAccessException<seq2seq4repair_space>occurred" , iae ) ; } catch ( InvocationTargetException ite ) { throw new RuntimeException ( "InvocationTargetException<seq2seq4repair_space>occurred" , ite ) ; } catch ( SecurityException se ) { throw new RuntimeException ( "SecurityException<seq2seq4repair_space>occurred" , se ) ; } } private static String removeAccentsJava6 ( CharSequence text ) throws IllegalAccessException , IllegalArgumentException , InvocationTargetException { } private static String removeAccentsSUN ( CharSequence text ) throws IllegalAccessException , IllegalArgumentException , InvocationTargetException { } private static boolean sunAvailable = false ; private static Method sunDecomposeMethod = null ; private static final Pattern sunPattern = Pattern . compile ( "\\p{InCombiningDiacriticalMarks}+" ) ; private static boolean java6Available = false ; private static Method java6NormalizeMethod = null ; private static Object java6NormalizerFormNFD = null ; private static final Pattern java6Pattern = StringUtils . sunPattern ; public static boolean equals ( CharSequence cs1 , CharSequence cs2 ) { } public static boolean equalsIgnoreCase ( String str1 , String str2 ) { } public static int indexOf ( CharSequence seq , int searchChar ) { } public static int indexOf ( CharSequence seq , int searchChar , int startPos ) { } public static int indexOf ( CharSequence seq , CharSequence searchSeq ) { } public static int indexOf ( CharSequence seq , CharSequence searchSeq , int startPos ) { } public static int ordinalIndexOf ( String str , String searchStr , int ordinal ) { } private static int ordinalIndexOf ( String str , String searchStr , int ordinal , boolean lastIndex ) { } public static int indexOfIgnoreCase ( String str , String searchStr ) { } public static int indexOfIgnoreCase ( String str , String searchStr , int startPos ) { } public static int lastIndexOf ( CharSequence seq , int searchChar ) { } public static int lastIndexOf ( CharSequence seq , int searchChar , int startPos ) { } public static int lastIndexOf ( CharSequence seq , CharSequence searchSeq ) { } public static int lastOrdinalIndexOf ( String str , String searchStr , int ordinal ) { } public static int lastIndexOf ( CharSequence seq , CharSequence searchSeq , int startPos ) { } public static int lastIndexOfIgnoreCase ( String str , String searchStr ) { } public static int lastIndexOfIgnoreCase ( String str , String searchStr , int startPos ) { } public static boolean contains ( CharSequence seq , int searchChar ) { } public static boolean contains ( CharSequence seq , CharSequence searchSeq ) { } public static boolean containsIgnoreCase ( String str , String searchStr ) { } public static boolean containsWhitespace ( CharSequence seq ) { } public static int indexOfAny ( CharSequence cs , char ... searchChars ) { } public static int indexOfAny ( CharSequence cs , String searchChars ) { } public static boolean containsAny ( CharSequence cs , char [ ] searchChars ) { } public static boolean containsAny ( CharSequence cs , CharSequence searchChars ) { } public static int indexOfAnyBut ( CharSequence cs , char [ ] searchChars ) { } public static int indexOfAnyBut ( CharSequence seq , CharSequence searchChars ) { } public static boolean containsOnly ( CharSequence cs , char ... valid ) { } public static boolean containsOnly ( CharSequence cs , String validChars ) { } public static boolean containsNone ( CharSequence cs , char ... searchChars ) { } public static boolean containsNone ( CharSequence cs , String invalidChars ) { } public static int indexOfAny ( CharSequence str , CharSequence [ ] searchStrs ) { } public static int lastIndexOfAny ( CharSequence str , CharSequence [ ] searchStrs ) { } public static String substring ( String str , int start ) { } public static String substring ( String str , int start , int end ) { } public static String left ( String str , int len ) { } public static String right ( String str , int len ) { } public static String mid ( String str , int pos , int len ) { }

Fix:
public static String stripAccents ( String input ) {